5 years & up. Build your own working electronic circuits by piecing together magnetic circuit blocks in a variety of different combinations with the Magnatronix Starter and Expansion Set. Take on the challenge of following the circuit pattern ideas featured in the activity guide or make up your own circuit patterns as you learn the basics of systems engineering. Develops children's fine motor and problem-solving skills through STEM-based play. Both the Starter and the Expansion pack require 3 AA batteries (not included). Starter includes: Switch, Battery Pack, Buzzer, LED, Motor, 5 Direction Pieces, Helicopter, and an Activity Guide. Expansion includes: Switch, LED, Pulser, Dial, 5 Direction Pieces, and an Activity Guide.